Refrigerator shelf



FIG. 1 is a perspective view of a refrigerator shelf according to the design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a back elevation view thereof;

FIG. 4 is a right side elevation view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The portions of the article shown in even broken lines form no part of the claimed design.

Dash-dot-dash broken lines adjacent un-shaded areas represent bounds of the claimed design and form no part of the claimed design themselves. 

CLAIM The ornamental design for a refrigerator shelf, as shown and described. 